The worst thing a kid can say about homework is that it is too hard. The worst thing a kid can say about a game is it's too easy.Henry Jenkins
Hardcore mode in Call of Duty typically removes "quality of life" features that most first-person shooters employ. The mode typically removes HUD elements like mini-maps, ammunition indicators, and my favorite: crosshairs.
What implicit challenges are in First Person Shooter games typically? What does the hardcore mode on Call of Duty do to those implicit challenges already present? How important are implicit challenges to a lifespan of a game?
In your group, decide how you will create an immediate challenge for the players, but then also provide challenges that will emerge over the lifespan of the game. How might XYZ see your decisions as they relate to skill-based gameplay?